Knowledge Base

Synchronize Computers With A Network Time Protocol

Aim

To synchronize face analysis with stimulus presentation. The clocks of the test participant PC and the FaceReader PC must be exactly the same. We recommend to set the two clocks to the same time using a Network Time Protocol (NTP) server. Noldus has tested the Stimulus Presentation Tool with NetTime version 3.14.

Prerequisite

You use the Stimulus Presentation Tool on another computer than the one with FaceReader.

Procedure

The following steps are needed on both PCs:

1. Install NetTime
2. Adjust the NetTime Settings
3. Create exceptions for NetTime in Windows Firewall
4. Before the start of a test with Stimulus Presentation Tool, synchronize the two PCs. You can also choose to do this automatically at regular intervals (minimum 15 minutes).

   See Synchronize The Test PC To The FaceReader PC

Install NetTime

Do the following on both FaceReader and test PCs:

1. Browse to http://www.timesynctool.com, and download the latest version of NetTimeSetup.exe.
2. Run the installation file. During installation, select Install as Service (Recommended).

Adjust The NetTime Settings

1. Click the arrow in the lower-right corner of your screen to open the system tray.
2. Click the Network Time Synchronization icon.
3. Click Settings.
4. Under Hostname or IP Address:
   • For the FaceReader PC — Leave the Time Servers names as shown in the next table.
   • For the test PC — In the first Time Servers field, enter the name of the FaceReader PC, and delete all other external Time Servers. See the following table.

   	FaceReader PC	Test PC
   Time Servers	0.nettime.pool.ntp.org	[FaceReader PC's name]
   	1.nettime.pool.ntp.org	[empty]
   	2.nettime.pool.ntp.org	[empty]
   	3.nettime.pool.ntp.org	[empty]
   Update Interval	15 minutes	60 seconds

   To find the name of a PC, right-click My Computer and choose Properties.

5. Choose SNTP as Protocol and 123 as Port.
6. Next to Update Interval enter (see also the table above):
   • For the FaceReader PC — 15 minutes.
   • For the test PC — 60 seconds.
7. For the FaceReader PC only — Select Allow other computers to sync to this computer.
8. For both PCs —
   • Select Show NetTime icon in the system tray at login and Start NetTime service at bootup.
   • De-select Demote Servers after [ ] failures.
   • Next to If time adjustment greater than, select 10 milliseconds, then Adjust System Time.
9. Click OK. When a warning appears about Update Intervals being lower than 10 minutes (on the test PC), click No.

Create Exceptions For NetTime In Windows Firewall

To prevent that syncing fails because of the Firewall, create exceptions on both PCs as follows.

1. In the Windows' Search field, type firewall, and under the results click Windows Defender Firewall.
2. Turn on the firewall for all networks, then click OK.
3. Click Advanced Settings.
4. Inbound Rule
   • On the left panel of the Windows Defender Firewall and Advanced Security window, click Inbound Rules and on the right panel under Actions choose New Rule.
   • In the New Inbound Rule Wizard, on the Rule Type page, choose Program, then click Next>.
   • On the Program page, select This Program path, click Browse and select the file C:\ProgramFiles (x86)\NetTime\NetTimeService.exe.
   • Then click Open and Next>.
   • On the Action page select Allow the connection, then click Next>.
   • On the Profile page select all options Domain, Private, and Public. Then click Next>.
   • On the Name page, enter a Name (for example NetTime Service). Then click Finish.
5. Outbound Rule
   • On the left panel of the Windows Defender Firewall and Advanced Security window, click Outbound Rules and on the right panel under Actions choose New Rule.
   • Repeat step 4 above to complete the Outbound Rule. Make sure you choose the same options as for the Inbound Rule.
6. Repeat all steps above for the other PC.

Note

If you followed all procedures for establishing Firewall exceptions (Create exceptions in Windows Firewall for Stimulus Presentation Tool and Create exceptions for NetTime in Windows Firewall), each computer should have two Inbound Rules and two Outbound Rules:

• One for the port (for communication between FaceReader and Stimulus Presentation Tool)
• One for NetTime Service.

Synchronize The Test PC To The FaceReader PC

1. Always start the test PC after starting the FaceReader PC. This ensures that the test PC always finds its time server.
2. On the test PC, click the arrow in the lower-right corner of your screen to open the system tray.
3. Click the Network Time Synchronization icon.
4. Make sure that the first item under Server Name is the name of the FaceReader PC. If this is not the case, click Settings and enter the FaceReader PC's name for the first time server.

   See Adjust The NetTime Settings

5. Click the Update Now button.

   The Offset and Lag are updated. Please note that you may get an error if the test PC is in another network.

Source: FaceReader 10 Reference Manual (Help), Noldus Information Technology